PRIMES LDS software (PRIMES LASER DIAGNOSTIC SOFTWARE) is a well known tool for M2 measurements for laser beams. Anyone working with the software? Want to know the reason for taking multiple planes to measure M2. When we want to take a final result, which plane should be looked in to? If we are measuring a closer to a single mode beam, does each plane should give a Gaussian intensity distribution?
Hi Chathurangani
I am not familiar with the PRIMES laser diagnostic software, but the reason for taking profiles in multiple planes is that the M2 factor characterizes how close to diffraction limited is the laser beam. You need a few measurements close to the beam waist to accurately determine its minimum size and several measurements 1-2 Rayleigh lengths away from the beam to characterize the beam divergence. Yes, for a near single mode beam (M2 close to 1) the transverse profile should be Gaussian.
Best of luck
Michael
M2 'yi bir veya birden fazla düzlem alınabilir. Örneğin sadece x veya x, y, z düzlemi. Lazer ışınları tek boyutlu, iki boyutlu, üç boyutlu veya daha fazla boyutlu olabilir. Bu durum lazer ışınlarının yoğunluğuna ve uygulanacak gauss eliminasyon yöntemine bağlı olarak değişir. Aynı şekilde her düzlem bir gauss yöntemini verebilir, iki veya üç düzlem tek gauss yöntemini verebilir ve aynı veya farklı şekilde gauss kanunu tek düzlemde toplanabilir.
Dear Chathurangani,
as Michael already pointed out, the measurement of M2 needs the profile in multiple planes of the beam caustic. As the product of beam waist and far field divergence (hence the name "beam parameter product"), both regions have to be measured, typically at at least 10 positions. The details can be found in the ISO standard 11146 and is implemented in the LDS.
Regarding the question of which plane to look at, it depends a bit on what your interested in. But yes, as already mentioned, a fundamental TEM00 (gaussian) mode would be shape-invariant (just scaling) along the propagation. By the way, pure higher TEM modes are also shape-invariant, although with a higher M2 value.
Best
Andreas
- Badges
- Science topic
- Similar topics
- Computer Communications (Networks)
- Simulators